Using boring machines with a steerable bit or head for drilling horizontal boreholes under a roadway or other obstruction is a well known practice. The process of providing such boreholes is generally referred to as "trenchless" digging, since an open trench is not required. A key to the operation of such a boring device is to have an effective steerable boring bit or head. If the bit is steerable, the operator can redirect the borehole along the proper path if it begins diverting from the desired path, and also allows the operator to steer around obstructions underground.
Many drill bits have been designed which have such a steering feature. However, there is a continuing need to develop boring bits which have better directional control, operate in a variety of soil conditions effectively and provide enhanced cutting action.